Safety device for pipe-cutting machines



Jame 5, 1923. 1 1,457,992

' H. MORRISQN SAFETY DEVICE FOR PIPE CUTTING MACHINES Filed May 25. 1921 Patented June 5, i923.

siren il ti HACKLEY aronnrson, or RICHMOND, VIRGINIA.

SAFETY DEVICE FOR PIPE-CUTTING MACHINES.

Application filed May 25, 1921. Serial No. 472,456.

T 0 all whom it may concern Be it known that I, HAoKLnY lalonnison, a citizen of the United States, residing at Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Safety Devices for Pipe-Cutting Machines, of which the following is a specification.

This invention relates to pipe cutting machines, and more particularly to machines of the type shown in my prior co-pending application S. N. 391,717, filed June 25, 1920.

In such prior application, I have shown an arm carrying the pipe supporting rolls, and a weighted lever on which such arm is pivoted, such lever being arranged to yield when the pressure on the pipe-exceeds a safe limit, so as to prevent injury to the machine and damage to the pipe.

WVhile th s automatically yielding arrangement is of great practical value, I find that it is desirable to superpose upon such automatic control, a manual control. It is, therefore, the object of the present invention to provide means whereby the pressure on the pipe can be manually relieved by the operator at will, without the necessity of depending wholly upon or waiting for the action of the automatic mechanism.

Specifically, the invention contemplates the provision of manual means for applying aforce to the weighted'lever, above mentioned, in a direction opposite to that in which the weight acts, such force serving either to partially nullify the action of the weight, thus lessening the pressure, or to completely lift the weight, and with it, the lever, thus entirely" relieving the pipe of ressure.

lVhile I have shown the invention as applied to a machine having a weighted lever, as described, it will,.of course, be understood that it isunot limited to such application. The present improvements consist, broadly, in providing a machine for cutting off pipe, having apower-operated feed, with manual means by which the pressure on the pipe may be quickly relieved, asoccasion demands, at any stage of the cutting operation, should the pipe fail to rotate, orshould, for any other reason, the pressure tend to become excessive; 1 I In orderthat; the invention may be readily understood, reference is had to the-aecompanying drawing forming part of'this specification, and in which 1 I Fig. 1, is a vertical section through a pipe cutting machine, equipped with the present improvements, and

Fig. 2, is a fragmentary sectional plan thereof on the line 2-2 of Fig. 1.

Referring to the drawings in detail, the machine herein illustrated by way of example, is of the same type as that shown in my prior co-pending application above re ferred to.

The machine comprises a bed 1 and a suit able supporting frame 2. 3 designates a cut ter disc which isrigidly mounted upon a shaft 4, continuously rotated by suitable means, (not shown). The pipe 00 to be cut, is supported on a pair of rolls 5 journaled in a cage 6 carried by a lever 6. To the lever 6 is'pivotally connected at 7, the lower end of a yoke S, in the upper part of which is adjustably mounted a block 9, such adjustment being effected by means of a handwheel 12. In the block 9 Works an excentric 10 carried by a power shaft 11, driven in any suitable way.

A bracket 13 is fixed to the bed of the machine and to the upper end of such bracket is pivoted at 15 lever 14 on which a weight 17 is adjustably hung. Downward movement of the lever 14 is limited by a supporting bracket 18 secured to the bed of the machine;

Set into the lever 14 adjacent the pivot 15 is an adjustable screw 16 operated by a handwheel 16. The lower end of this screw bears against the end of lever6 and constitutes a fulcrum about which the lever 6 normally turns. The parts so far described, in construction and operation .are the same as shown in my above'identified co-pending ap plication. r

As fully explained in said application,-the purpose of the above described (onstruction, is to prevent, damage to'the pipe or the cutter. When the pressure on the pipe becomes excessive, the reaction of the end of lever 6 on the screw 16, lifts the lever 14 slightly, thus permitting the supporting rolls 5 to yield and thus relieve the pressure.

I have found it desirable, however, to pro-v vide, in addition to the above described automatic device, manual means for relieving the pressure on the pipe at any time-during the cutting operation. To this end, I attach to the lever 14 a hand lever or arm extending forwardly to a point Within easy reach of the operator, so that the operator, by grasping such hand lever, can at any moment, swing the lever 14; about its pivot and thus relieve the pressure on the pipe. In practice I prefer to provide a plurality of such I and secured in position by lock nuts By means of .these nhand-levers, it will be seen that the opera or can, when desired, exert a force on the lever 14, tending to swing the same on its pivot 15in a direction opposite to that in which the lever is urged by the weight. If such force is only slight, it will serve to partially counteract the effect of the weight and thus lessen the pressure on. the pipe; if the force is greater, it will serve to; actually lift the weighted lever and thus entirely relieve the pipe of pressure. 7

Power operated feed, pipe cutting machines of the disc type, have heretofore been open to the objection that the pipe is liable to be crushed by excessive pressure due to some defect or failure of the pipe to rotate properly, and by providing means under the control of the operator for instantlyrelieving the ressure on the pipe as above described, I am able to entirely overcome this objection and to reduce to a minimum the chance of damage to the machine or the plpe.

While I have shown only a manual lever, and while I have used the word manual in the accompanying claims, it will of course, be understood that'by such term-I also intend to include means operated by a foot pedal or the like, as well as by hand.

1. Ina pipecutting machine, the combination with supporting rolls and a cutter disc, of power operated means for moving the one toward the other, in a path passing through the axis of the disc, to effect a cut,

and manual means for regulating at will during the cutting operation, the pressure on the work held between the rolls and cutterdisc. 1

- 2. In a pipe cutting machine, the combination with supporting rolls and a cutter disc, of power operated means for moving the one toward the other to effect a cut, and

' a manually operated pivoted lever for relieving, at any desired stage of the out, the

and cutter disc.

pressure on the work held between the rolls 3. In a pipe cutting machine, the combination with supporting rolls and a cutter disc, of power operated means for moving the one-directly toward the other so as to press the work and cutter disc together to effect a cut, and manual means for relieving the pressure on'the work held between the rolls and cutter disc, should such pressure at any time become excessive.

4. In a pipe-cutting machine, the combination with supporting rollsand a cutter disc,'of power operated means for moving the one toward the other to effect a cut, automatic means for limiting to a predetermined possible maximum the pressure on the work held between the rolls and cutter.

disc, and additional manual means for also relieving such pressure at will.

5; In a pipe cutting machine, the combination with cutting elements comprising supporting rolls and a cutter disc, of an in which one of said elements is carried, au-

tomatic means for applying power to said arm to move the carried element toward the other, a movable pivotal support for said arm, means for normally holding said support rigid, and manual means for movmg said support when required. i

7. In a pipe cutting machine, the combination with cutting elements comprising supporting rolls and a cutter disc, of an armfin which one of said elements is carried, automatlc means for applylngspower to sald arm to move the carried element toward the other, a normally rigidpivotal support for said arm, said support having, means permitting it to yield whenever the pressure on the rolls exceeds a predetermined amount, 7

and manual means for causing said support to yield whenever desired.

8. In a pipe cutting machine, the combination with cutting elements comprising supporting rolls and a cutter disc, of an arm in which one of said elements is carried, automatic means for applyingv power to said arm to move the carried element toward the other, a normally rigid pivotal support for a said arm, said support having-means per mitting it to move whenever" the pressure of the'rolls exceeds a predetermined amount, and manual means for positively moving said suppor as desired.

9. In a pipe cutting-machine, the combination with cutting elements comprising a cutter disc and supporting rolls, of an arm m which one of said elements is journaledp a movably mounted support on which said arm is pivoted, power operated means for swinging said arm on its pivot, said means acting upon the arm at such a point that the pressure of the cutter disc against the work is opposed and sustained by the thrust of the arm against said movably mounted support, and manual means for moving said support when desired, to relieve such pres- 10 sure.

10. In a pipe cutting machine, the combination with cutting elements comprising a cutter disc and supporting rolls, of an arm in which one of said elements is journaled, aweighted lever on which said arm pivots, power operated means for movingsaid arm toeffect' a cut, and manual means for applying force to said lever, when desired, in a direction opposite to that in which the weight acts. v

In testimony whereof I afiix my signature.

HAGKLEY MORRISON. 

